Pressure vessels are utilized in many industries for manufacturing products when maintaining specific temperatures and pressures is required. Industries using pressure vessels include but are not limited to pharmaceutical, chemical, food and beverage, medical, biotechnical, ethanol, dairy, water treatment, paper, cryogenic, and other industries requiring chemical or biological processing in a pressurized environment. The processes that require the use of pressure vessels often require devices or other instrumentation to measure and control operating conditions such as temperature, pressure, liquid level, and other parameters through various known instrumentation. Further, these industries may also require pressure vessels to have inlets, outlets, or ports to introduce or remove contents, obtain samples of the contents of the tank while maintaining a sterile or sealed environment, or perform other related actions. Split ring connections and tri-clamp connections have become standard universal connections in the pressure vessel industry and allow instrumentation, inlets, outlets, ports, sight glasses or other apparatuses to be connected to a pressure vessel.
Split ring connections, such as the NovAseptic® connector, and the ASEPCONNECT™ connector, are well known in the art and utilize a base welded to the pressure vessel and a split retaining ring. The instrumentation is secured in the base by the split retaining ring that, when tightened, engages the instrument's ferrule and compresses the ferrule and an elastomeric seal against a seat in the base thereby effectuating the connection. The compression required to create the seal and connection is created using four or more threaded fasteners or bolts that can be tightened to achieve a desired compressive force and resistance.
A large number of pressure vessels manufactured and in use today are outfitted with bases designed for utilizing split ring connections. However, these bolted split ring connections have several drawbacks. The first problem relates to their inability for allowing instrumentation to be quickly removed, exchanged or replaced. When an operator desires to remove, exchange or replace instrumentation held in place by a split ring connection, the operator locates the properly sized wrench and removes at least four buts or bolts. This can be a time consuming task. Second, in removing the nuts or bolts, occasionally the operator will inadvertently “strip” the threads within the base or the bolts extending from the base. When this occurs, the pressure vessel is deemed unusable until the base can be replaced. Replacing such a base in a pressure vessel may require the skill of an ASME-certified welder and can cost tens of thousands of dollars. Additionally, if the pressure vessel contains any product therein, the product is often times worth hundreds of thousands of dollars and may have to be discarded. A further shortcoming of the split ring connection occurs when an operator drops or misplaces the nuts or bolts, requiring yet additional time and effort to retrieve or replace the nuts or bolts.
Another shortcoming of bolted split ring connection relates to the thickness of the split ring itself. The two or more sections of the split ring act independently of one another. Split rings are often necessary because a solid retaining ring is not able to be installed over existing instrumentation. Because the split retaining ring sections act independently, the bending forces exerted on the sections' free ends require the ring to be of an increased thickness as compared to a solid (i.e., continuous and non-split) ring. The split ring's increased thickness sometimes presents clearance issues with the instrumentation held in place by the split ring.
Tri-clamp connections, such as the ASEPCO QUICKONNECT™, are well known in the art and utilize a tri-clamp or other known sanitary compression clamp to create a compression clamping force to join the apparatus or instrument to a dead leg. Tri-clamp connections generally use an elastomeric seal compressed or sandwiched between the two pieces being joined thereby creating a connection that is air tight and can withstand the required elevated pressure conditions. In the typical tri-clamp connection, two beveled flanges are received within and clamped together with a clamp. Many conventional tri-clamp connections known in the art include dead legs in order to extend the connection away from the surface of the vessel. The typical dead leg includes a spacer tube that is welded to the wall of a pressure vessel at one end and terminates in a beveled flange at the opposite free end. The beveled flange of the dead leg is positioned at a distance away from the vessel wall. The spacer tube of the dead leg introduces a recessed area in the interior surface of the vessel that is difficult to clean thoroughly. Because it is difficult to visually inspect and direct cleaning solutions into dead legs, contaminants can remain present even after the interior of the vessel is thought to be clean. This is especially worrisome in industries with strict sanitary requirements, or that have elevated legal liability if their products contain impurities, such as the pharmaceutical, food and beverage, or chemical industries.
Tri-clamp connections have become popular because they maintain the pressure capacity of the system, yet are easy to disassemble. The ability to easily disassemble the connection makes it easy to clean or replace the instrumentation, attachments, and clamps thereby facilitating the maintenance of a sterile environment. However, the dead legs often associated with such connections can cause cleanliness and sterility issues.
As mentioned above, a large number of pressure vessels manufactured and in use today are outfitted with bases designed for utilizing split ring connections, not tri-clamp connections. The task of replacing a base configured for a utilizing split ring connection with a base or dead leg configured for utilizing a tri-clamp connection is a substantial undertaking that may require the skill of an ASME-certified welder and can cost tens of thousands of dollars. Furthermore, the bases designed for utilizing split ring connections do not generally have the shortcomings of the dead legs configured for utilizing tri-clamp connections.
Therefore, a need exists for an assembly allowing an operator to transform a connection assembly having a base configured for a bolted split ring connection to a clamped connection assembly that uses tri-clamps or other sanitary clamps known in the art. Additionally, a need exists for an improved split retaining ring having a reduced thickness to decrease the total depth of the connection so as not to interfere with the instrumentation it is holding in place.